The present invention relates to a polyarylene thioether (hereinafter referred to as "PATE") composition which has a high crystallization rate and a fine spherulite structure.
The present invention also relates to a PATE composition which has a short cycle of melt molding and produces a molded product having excellent mechanical properties.
More particularly, the present invention relates to a PATE composition which comprises 100 parts by weight of PATE (A) containing not less than 70 wt % of repeating unit of ##STR3## and 0.01 to 15 parts by weight of PATE (B) which contains not less than 50 wt % of repeating unit of ##STR4## and has a melting point (hereinafter referred to as "Tm") of not lower than 290.degree. C. or a melt crystallizing temperature (Hereinafter referred to as "Tc.sub.2 ") of not lower than 220.degree. C. and which is added to PATE (A) as a nucleating agent.
PATE is a resin developed as a heat-resistant, chemical-resistant and flameresistant thermoplastic resin. Particularly, since PATE is crystalline, PATE can be melt processed with injection molding, extrusion molding, etc. and has a characteristic points that molded products obtained from PATE are excellent in physical properties such as dimensional stability, strength, hardness, and insulating property.
Taking advantage of this characteristic point, PATE is used in the fields of electricity, electronics, cars, aeroplanes, precision machinery and chemical engineering, etc.
However, the conventional PATE has a defect that its crystallization rate is low and accordingly often results to have coarse spherulites.
Because of the above defect, when PATE is fabricated, for example, with injection molding, there has been a problem which lead to practical defects such as long molding cycle, many occurrence of flashes and low mechanical properties of molded products.
As a result of extensive studies on a nucleating agent effective to PATE, the present invention have found that use of a PATE (B), which contains not less than 50 wt % of repeating unit of ##STR5## as the main constituent and has Tm of not lower than 290.degree. C. or T.sub.c2 of not lower than 220.degree. C., as a nucleating agent, produces an excellent effect, namely, improvement of the crystallization rate and reduction in spherulite size. The present invention has been achieved on the basis of these findings.